Anyone know anything about disc brakes?

Do I need the hose cutter and barb tool to put hoses on or can I make do with some plumbing snips that make a neat job on 15mm barrier pipe?

It’s routing that bothers me. How likely is it I’ll need to take the BB out?

I’m trying to avoid a minimum two week wait at my LBS which won’t allow you to book a bike in on a specific day.

I use those yellow clamping pads that Shimano put in with their brakes held in a vice to give me a straight line and solid grip and then a new stanley knife blade to cut the hose. Then I gently tap in the barb with a light hammer. Not been a problem so far.

^what he said. Or mole grips work if you don't have a vice.

Routing is more difficult to predict, what are you planning to change? What's the bike?

RX4s sound great, but 4 pistons calipers for road bikes has me wandering.. Do you all live in the Alps?
I get the bling and would happily splurge as well, but is there an actual need?

are you going back to rim brakes? if not buy the right tools. Aliexpress tools are just fine, the tektro hose cutter and barb pusher is good.

I’m trying to avoid a minimum two week wait at my LBS

My primary reason to buy niche tools these days.

Mole grips with Shimano clamping pads, hold it next to a cutting surface and cut as square as possible with a cutter. Do a couple of test cuts first, then final cut to correct length.

Snips might do a good job, but you risk crimping the hose

I’m only replacing the hoses because there’s a hose connector on each between the head tube and the point where I want to route them through the bars.

This is the bike.

3 Attachments

buy this

4 pot brakes in theory allow for better modulation, especially with the differing size pistons.

I chose to put some on my road bike though because I don't like SRAM/Avid calipers and moar purple is moar better.

4 pots with same levers/reservoir must also mean less volume displacement at the caliper/less piston travel, correct? Does that mean you get some rubbing from time to time?

Only if the overall surface area of the pistons is greater. The 4 Hope pistons are all smaller than the SRAMS so I'd wager it's very similar.

TBH all disc brakes rub from time to time IME

That sent my cable OCD trough the roof.
Chopping the hoses has been explained enough. Now, to route it around the bottom bracket, and without seeing how exactly it works in your frame, the easy solution would be to leave a guide as you remove the old hose, then using that to yank the new one back to place. The Park Tool internal routing kit have something you can use, or you can try to improvise a way. Depends on how annoying is to go around the BB and how tiny are the holes really.

Thanks - I’ve ordered one from a U.K. eBay seller. I’m not convinced by the cutter. It looks like those classroom scissors.

Incase anyone missed the discussion a few days ago
50 quid repair is live
Hope rx4 is a repair right !

https://fixyourbikevoucherscheme.est.org.uk/

the easy solution would be to leave a guide as you remove the old hose, then using that to yank the new one back to place

Or chop the ends off the old hose, join the new hose to the old hose with one of these:

and use the old hose to pull the new hose through.

How likely is there to be a foam lining around the hose in the down tube?

Obviously I can’t pull anything through a piece of foam.

Sram could solve this with wireless brakes.

Isn’t there a risk something as hard as that will damage the inside of the frame?

You’re probably right but another tool that probably means it’s going to be more economical to send it to the bike shop.

As long as the blade is sharp and it makes a straight cut without pinching the hose it will work. I have the same and have done many hoses, all good.

Isn’t there a risk something as hard as that will damage the inside of the frame?

No, none at all - it's tiny. The diameter of the centre section is less than the diameter of the hoses attached to each end, and only a few mm long, so there's no realistic way it's going to hit any part of the inside of the frame. Due to its diminutive size it's a right PITA to install and remove, and annoyingly easy to misplace, but it works really rather well.

How likely is there to be a foam lining around the hose in the down tube?

Very unlikely. Almost all carbon frames are made using internal bladders to compress the carbon laminate against the outside of the mould, so they're hollow. There are some frames made with foam cores, but that's a pretty outdated method of construction. Anyway, there must have been some way of installing the hoses in the first place, so all you need to do is replicate that...

Sorry - I meant a foam liner around the hydraulic hose in the downtube.

Some bikes seem to have them fitted to stop rattling.

Ah, dunno. Never seen that before. How do they put the foam liner in place if it's bigger than the brake hose and so won't fit through the entry hole?